Small but important machine part (3)
I believe the answer is:
cog
(Other definitions for cog that I've seen before include "Machine wheel" , "Projection on a toothed wheel" , "bar" , "Each of series of teeth on wheel" , "Machine component" .)
I believe the answer is:
cog
(Other definitions for cog that I've seen before include "Machine wheel" , "Projection on a toothed wheel" , "bar" , "Each of series of teeth on wheel" , "Machine component" .)